On the Lithuanian side, the lake and its environs are part of a protected area named Vištytis Regional Park.

[2] This is a marked increase over 0.4 km2 (0.15 sq mi) that belonged to Lithuania before ratification of a Russian–Lithuanian border treaty in 2003.

[4] On occasion, high winds or broken equipment can force tourist boats to the opposite western shore.

[5] Before the 2003 treaty, the border ran along the waterline of the beaches on the Lithuanian side, so anyone paddling in the water was technically crossing into Russia.

[7] Prior to World War II the lake formed part of the border between the German province of East Prussia and Lithuania.